BOSTON – Ray Allen left as a free agent. Rajon Rondo is out for the season. Kevin Garnett is recuperating from an ankle injury.

With the core of the Celtics team that won the franchise’s 17th NBA title in 2008 otherwise occupied, Jeff Green led Boston back into the playoffs.

The Celtics swingman scored 34 points, including a 3-pointer with 45 seconds left to snap a two-minute scoring drought, to help Boston beat the Detroit Pistons, 98-93, last night and clinch the team’s sixth consecutive playoff berth.

“We knew we were a playoff team before the season started, despite the injuries and everything,” said Paul Pierce, the only healthy holdover from the team that won it all in 2008 and returned to the NBA Finals two years later.

“The playoffs is a totally different game; it’s nothing like the regular season. At least these guys will go out there and get their feet wet, see some shots go in, rebound the ball and get some experience.”

Pierce and Brandon Bass scored 17 apiece, and Bass added seven rebounds for the Celtics, who had lost two in a row and seven of their previous nine.

The victory, coupled with Philadelphia’s 88-83 loss to the Charlotte Bobcats, left Boston 8 ½ games ahead of the 76ers with eight games to play. It’s the sixth consecutive season Boston has reached the playoffs since the New Big Three was assembled in the summer of 2007.

Even with Allen gone and Garnett missing seven straight games with an injured left ankle, the Celtics are back in the postseason. Boston is seventh in the Eastern Conference, two games behind sixth-place Chicago and 2½ ahead of eighth-place Milwaukee.

“There was never any doubt in my mind or anybody in the locker room that we wouldn’t be in the playoffs,” said Jason Terry, who had 10 points and five rebounds.

Green came to Boston in the 2011 trade that sent Kendrick Perkins to Oklahoma City, but he missed all of last season after heart surgery.

Now he looks like the Celtics’ best hope of making a postseason run.

“Jeff’s a very, very good player, and I think (that’s) what you’ve seen,” Pistons Coach Lawrence Frank said. “He got off to a tough start this year and obviously he had major, major, life-threatening surgery last year. ... I didn’t like to see him do well tonight, but by and large every other game you pull for him, especially with what he went through.”

Green scored 13 points in the fourth quarter and added six rebounds and four blocked shots in the game. He has become one of the players the Celtics look to for big plays as the clock runs down, sharing the role that Pierce had occupied for more than a decade.

“I don’t try to take over games. We have ‘the Truth,’ ” Green said, calling Pierce by his nickname. “We feed off each other. If it’s in my hands, I try to make a play. If it’s in his hands, he’ll try to make a play. We’re playing off each other.”

Greg Monroe had 24 points and 17 rebounds and Rodney Stuckey scored 22 for the Pistons.

The Celtics led by as many as 18 points before the Pistons scored the final 11 points of the third quarter and opened the fourth with Jonas Jerebko’s three-point play. Boston went into another scoring slump late in the fourth, going 2 minutes, 9 seconds without a point while Detroit cut a 93-87 deficit down to two points.

But Green hit a 3-pointer from the left corner to give Boston a 96-91 lead. After Monroe got free for an easy dunk on an inbounds play, Terry missed; Charlie Villanueva, who went 2-for-17 from the floor and missed all eight 3-point attempts, missed from beyond the arc for Detroit.

Terry made a pair of free throws with 10 seconds left to clinch it.

“Just a rough night for me offensively. Couldn’t buy a basket,” Villanueva said. “Seems like there as a lid on the rim for me.”

In all, the Pistons had 25 offensive rebounds and took 22 more shots than Boston. But Detroit shot 37 percent from the floor, including 17 percent from 3-point range, while the Celtics made more than half of their 2-pointers and 7 of 20 from 3-point range.

Notes

∎ Monroe’s 17 rebounds were one short of a season high.

∎ Pierce returned after missing one game for what he told WEEI.com was the birth of his son, Prince Pierce.

∎ Rondo, who is recovering from a torn ACL, visited his teammates at yesterday’s shootaround with a knee brace on.

∎ The Pistons won both previous games this season, both in Detroit.

∎ Pistons G Jose Calderon was a late scratch with a sore right arm.

∎ The Celtics bench was called for a technical foul, apparently for arguing about foul calls with 3:19 left in the game and an eight-point lead.